Metallic package-binder strap



Dec. 10, 1940. J. w. LESLIE METALLIC PACKAGE-BINDER STRAP Filed June 12,1939` a, Qc@

, Patented Dec, 10, 1940 22249189' METnLLrc PACKAGE-Binnen STRAP Joh-nW. Leslie, Chicago, lll., assgnor to Signode lSteel Strapping Company,Chicago, Ill., a cor`A Y poration of Delaware Application June 12, 1939,serial No; 278,681

v 4 claims. -(ci. 2li- 20)` My invention relates to metallicpackage-binder strap suchl as used for binding individual `packages andfor binding groups of lpackages into unitsthe results attained beingsecurity, reinforcement, ease of handling and reduction in` damageincident to shipment,

Ordinarily the binders are looped around and tensioned upon thepackageor group of packages and then overlapping portions are securely joinedand sealed together to render the encircling loop permanent. Since, thetension is usually applied by a `tool located at one side of a packageor group of packages it is important.'

cal examples) that the friction between superposed contacting portionsof binder be as low as possible, because such tools provide the tensioni 30 by sliding upon and past one another the superposed ends of thebinder loops. In order to provide for easy slippage between binder andpackage and between contacting portions of binder, it has long been thepractice to coat such strap 35 with a thin layer or film ofanti-friction material or lubricant, such as parai'line. Not only doesthe paraine provide the easy-slippage property, but italso protects thestrap against moisture and prevents rusting.

"40 On the' other hand, where the union or joint between the overlappingend portions of the tensioned binder loop is produced by crimping thoseportions together more or less edgewise-such,

. for example, as set forth in Flora Patent No.

45 1,252,680, in Leslie Patent N0. 1,445,330, or in Porter-Patent No.1,969,152-much of the joint strength depends upon the amount of frictionexistent between the binder surfaces which are in most intimateor closecontact with each other 50 within the joint, viz., in the edge regionswhere the principal deformation and closest engagement exist. n v

Thus, inshort, the surface characteristics de- K siredofpackage-binderstrap are low friction for `1.55 tension and high friction for strengthof crimped joints. Attempts have been made to provide binder. strappossessing these two diverse, notto say antagonistic, properties, but sofar as I am aware there hasl not been heretofore proposed anysatisfactory practical solution of the problem. As a matter of fact, thecommon practice 'of entirely coating binder strap with paraiiine orother lubricant in order to decrease the friction with the package, andthereby the better to distribute the tension, has Va rather markedjoint-weakening effect.`

' The object of my invention is to provide a metallicbinder strap which,to an adequate extent, will po'ssess both low and high surfacefriction.`

Another object is to provide a strap having these dual characteristicsand which lends itself to practical commercial production.

Inv general, my improved strap has a longitudinally `disposedarea-preferably centrally disposed relative Vto the edges--of relativelylow coefficient of surface friction and a longitudinally disposed edgearea-preferably along both edges-of relatively high coefficient ofsurface friction.

In the drawing:

l Fig. 1 is a plan of a portion of binder embodying my invention, and

Fig. 2 is a top plan of a typicalv joint of the edgewise folded orcrimped variety. ,30

I have found that if only the central longitudinal area of one surfaceof the strap is coated with a thin lm of anti-friction material orlubricant such as parafiine orother suitable substance of low frictioncoefficient, the desiredA easy-slippage characteristic of strap entirelycoated. with lubricant is not at all seriously im-y paired. For allpractical purposes it slips about package corners and upon itself aseasily as a completely lubricated strap.

I have also found that if the coefficient of surface friction is high inonly the .regions bordering the strap edges, the strength of crimpedjoints is very materially increased and yet the easyslippage property isnot materially reduced. 'I'he 45 width of the area of high surfacefriction coefficient to give thebest results will depend upon the depthof edgewise crimp employed.' It` should be wide enough so that the majorpart of the high-friction surface in the region of the 50 edgewise crimpwill be embraced Within the crimp where the overlapping strap portionsare mostY tightly pressed together.

In practice I have found that with a strap 5/8" wide good results areobtained if the paraf- 55 wheel partly immersed in a bath of thepara'ne.

heated to liquefaction or bya brush. Instead of applying the paraffinehot it may be cut or thinned to the proper consistency by suitable andwell known solvents, such as naphtha. When so applied, the evaporationof the solvent will leave the solici parafline in a very thin film uponthe `surface of the strap. y Y. l

The relatively high surface-coefficient stripes 6 along the edges of thestrap may be provided in various ways. Thusthese edge ystripes may beprovided by oxidizing or sand blasting, or otherwise roughening thestrap surface. As a matter of fact, for hot rolled strap, the oxidationof surface normal with this method of production will, under someconditions, lprovide the desired high frictionparticularly as the.surface becomes scaly during the deformation of `iointproduction. `Orthey. may be provided by coating the edge areas with asuitable highfriction'substance, such as resinous paints, of which shellac is ranexample. l Coating the edge areas is preferable to oxidizing orSandblasting because-like the lubricant-it can serve as a weatherproofprotection.

When a strap of `dual surface characteristics, such as heretoforedescribed, is looped and drawn tight about a package or group ofpackages the low friction or lubricated area provides easy slippage overthe package surfaces and, if tensioning tools of the type herenbeforementioned are used, between the superposed strap end porthe marginalareas will be obtained by treatment of only one side of the strap. Forother purposes, it will be desirable to obtain greater efliciency intensioning properties and in joint strength and `both sides of the strapmay be treated.

Having thus illustrated and explained the nature and an embodiment ofthe invention, what I claim and desire to secure by United StatesLetters Patent is as follows:

l. A metallic package binder strap having a flat unbroken surface with alongitudinally disposed arca of high surface friction and alongitudinally disposed area of low surface friction.

2f A metallic package binder strap having a fiat unbroken surface with acentrally disposed longitudinal stripe of low surface friction and anedge stripe of high surface friction.

3. A metallic package-binder strap having one of its flat unbrokensurfaces longitudinally and centrally striped with a lm of lubricant,which retains its place under ordinary conditions, and its edgesvtreated to provide high surface friction. i

4. A metallic package-binder strap having one of its flat unbrokensurfaces centrally and longitudinally coated with a lubricant, whichretains its place under ordinary conditions, and along the edges coatedwith aY high friction substance.

JOHN W.ALESLIE.

